[PATCH] vfat umas doc update

Fix the documentation to match the code fix.

Documentation/filesystems/vfat.txt

@@ -8,10 +8,12 @@ if you want to format from within Linux.
 
 VFAT MOUNT OPTIONS
 ----------------------------------------------------------------------
-umask=###     -- The permission mask (see umask(1)) for the regulare file.
+umask=###     -- The permission mask (for files and directories, see umask(1)).
                  The default is the umask of current process.
 dmask=###     -- The permission mask for the directory.
                  The default is the umask of current process.
+fmask=###     -- The permission mask for files.
+                 The default is the umask of current process.
 codepage=###  -- Sets the codepage for converting to shortname characters
 		 on FAT and VFAT filesystems.  By default, codepage 437
 		 is used.  This is the default for the U.S. and some